Main Header

A PENDATAHEADER structure is the first part of the main header of the HPENDATA object. The PENDATAHEADER structure, described in Chapter 11, "Pen Application Programming Interface
Structures," contains the following information:

Number of strokes

Total number of points

Number of points in longest stroke

Size in bytes of the memory block

Bounding rectangle of all pen-down points

Ink color

Ink width

Version

The wPndts member of the PENDATAHEADER structure describes the state of the data in the HPENDATA object. The state of the data reflects whether the data is compressed,
includes pen-up points, or includes OEM data. The wPndts element is a bitwise-OR combination of the PDTS_ flags described in Chapter
13, "Pen Application Programming Interface Constants."

The next component in the main header is a PENINFO structure. The PENINFO structure contains information about the tablet device that produced the
data. This information includes the tablet width, height, resolution, report rate,
proximity capabilities, and barrel-button status. For more information about
the PENINFO structure, see Chapter 11, "Pen Application Programming Interface Structures."

The cbOemData member of the PENINFO structure specifies how much (if any) OEM pen data each pen packet contains.
The format and order of the extra OEM information are contained in the rgboempeninfo member, which is an array of OEMPENINFO structures. The OEMPENINFO structures describe the order, minimum value, and scale of any OEM pen data
the tablet reports along with the coordinate data. Chapter 11 describes the OEMPENINFO structure in detail.